The British bank Standard Chartered agreed to pay $340 million to a United States financial regulator in August. The agreement was to settle charges that the bank illegally hid financial business with Iranian interests. The wording of the agreement notes that the financial business in question amounted to at least $250 billion.Standard Chartered said it "strongly rejects" the charges. The bank said it will fight efforts to withdraw its license to do business in New York, an important financial center. Standard Chartered is Britain's fifth largest bank. New York state's top bank regulator accused the bank of being a "rogue institution" from 2001 to 2010. The regulator said the bank made hundreds of millions of dollars in fees from about 60,000 financial exchanges with Iranian financial institutions. The reported exchanges were made through the bank's New York offices. One official said the dealings exposed the United States banking system to terrorists, illegal drug traffickers and rogue states. The United States Federal Bureau of Investigation is carrying out a criminal investigation. Other United States regulators also have opened investigations and are not part of the settlement.United States law has tightly controlled financial dealings with Iran since 1979. That year, 52 Americans were taken hostage in Tehran for 444 days. But western concerns about Iran's possible nuclear program are central to the case. Bank expert Bert Ely told VOA that the investigation is part of an effort by several Western countries to limit Iran's nuclear program. They accuse Iran of trying to develop a nuclear weapon.He said enforcement of the Bank Secrecy Act and other laws is part of an effort by financial officials to cut off money flows to Iran. This is to make it as difficult as possible for Iran to sell its oil around the world and to buy equipment and parts for nuclear enrichment activities. Standard Chartered is not the only British bank that has faced fines recently. Barclays agreed to pay fines of about $450 million dollars to American and British officials in July. Barclays is one of 18 banks that set an important measure of borrowing costs for banks, the London Interbank Offering Rate, or LIBOR. Officials said Barclays lied to them about its interest costs. This made the bank appear stronger than it was. But LIBOR is used to set many interest rates paid by millions of people around the world. For VOA Special English, I'm Mario Ritter. (Adapted from a radio program broadcast 17Aug2012)